Abstract

Resolving the age-distance relation of volcanism along the Walvis Ridge (southern Atlantic Ocean) is essential to understanding relative motion between the African plate and the Tristan-Gough mantle plume since the opening of the South Atlantic. However, tracking the location of the Tristan-Gough plume might not be practicable if most of the complex morphology of the massive Walvis Ridge is related to the proximity of the South Atlantic mid-ocean ridge. Here we use new 40Ar/39Ar basement ages for the Tristan-Gough hotspot track, together with information about morphology and crustal structure from new swath maps and seismic profiles, to infer that separated age-progressive intraplate segments track the location of the Tristan-Gough mantle plume. The apparent continuity of the inferred age-distance relation between widely separated age-progressive segments implies a connection to a stable or constantly moving source in the mantle.